不同贮藏温度对南美白对虾中甲醛含量变化的影响

本文研究了不同贮藏温度对南美白对虾中甲醛含量变化的影响。将南美白对虾分别贮藏于20、4、-5和-20℃条件下,贮藏过程中定期测定氧化三甲胺、三甲胺、游离甲醛和游离及可逆结合甲醛的含量并分析其变化趋势。结果表明在20、4和-5℃下,氧化三甲胺含量呈现降低趋势,腐败性物质三甲胺随着温度的升高增长速度变快,游离甲醛的增长速度随温度的降低而变缓;-20℃下贮藏至150 d,氧化三甲胺含量逐渐降低,游离及可逆结合甲醛含量增至6.46 mg/kg,游离甲醛增至3.09 mg/kg,增幅最大;三甲胺仅在贮藏后期有微弱的增长;各温度下,贮藏时间对游离甲醛含量变化的影响显著（p<0.05）,由此可见冻藏条件最有利于南美白对虾的保鲜,但产生的甲醛含量累积最多。本文为探究冻藏条件下控制甲醛的产生提供了一定理论支持。 

Study on the machanism of formaldehyde content changing in the Penaeus vannamei storaged at different temperatures

In this paper, taking Penaeus vannamei as the research object, the mechanism of formaldehyde content changing in the Penaeus vannamei storaged at different temperatures was explored. The contents of trimethylamine oxide, trimethylamine, free formaldehyde and reversible combined formaldehyde in samples stored at 20,4,-5 and-20 ℃ were detected termly and their variation tendency were analyzed. The result showed that,at 20,4 and-5 ℃,trimethylamine oxide showed a trend of decrease,corruptive trimethylamine content raised faster as the temperature went higher and free formaldehyde content raised slower as the temperature falled lower. In addition,trimethylamine oxide content gradually reduced and contents of free and reversible combined formaldehyde and free formaldehyde reached up to 6.46 mg/kg,3.09 mg/kg,with maximal increasing slope,in the sample stored for 150 days at-20 ℃,while trimethylamine turned out weak growth only in the late storage stage. At different temperature,the effect of storage time on formaldehyde content changing was significant(p<0.05). Thus it could be seen frozen condition most benefit for keeping penaeus vannamei fresh, but formaldehyde was produced and accumulated most. The study provided with theory support for controlling the formaldehyde producing in frozen storage condition.